Image display device, image display system, and image display method

ABSTRACT

An image display device includes a display unit that includes a plurality of display lines, an image data input unit that receives image data including data for each display line, and an image data transmission switching circuit that transmits the image data to the display unit.

This application is a Continuation application of U.S. patentapplication Ser. No. 14/413,931, which was filed on Jan. 9, 2015, andthe disclosure of which is incorporated herein in its entirety byreference thereto.

TECHNICAL FIELD

The present invention relates to an image display device, an imagedisplay system, and an image display method.

BACKGROUND ART

In recent years, there has been an increasing number of applications fordisplaying a single image on a large screen by multi-tiling, in which aplurality of image display devices such as liquid crystal displaydevices are combined (Patent Document 1). In such applications, thereare not only still images, but also numerous cases of displaying movingimages. When performing moving image display in this kind ofmulti-tiling, at the interface of the image display devices that areconnected side by side in the vertical direction, there is the problemof misalignment occurring between the image display device on the upperside and the image display device on the lower side.

PRIOR ART DOCUMENTS Patent Document [Patent Document 1] JapaneseUnexamined Patent Application, First Publication No. 2005-86592 SUMMARYOF THE INVENTION Problem to be Solved by the Invention

Here, the aforementioned problem shall be described in detail referringto FIG. 6 and FIG. 7. FIG. 6 and FIG. 7 are drawings prepared by theapplicants for describing the problems to be solved by the presentinvention. FIG. 6 (a) is a front view schematically showing a displayunit 115 of an image display device 101. FIG. 6 (b) is a front viewschematically showing a multi-tiling image display system 118 providedwith four image display devices 101 a, 101 b, 101 c, and 101 d.

In the example shown in FIG. 6 (a), the display unit 115 of the imagedisplay device 101 has 1080 image lines from line 1 at the top edge toline 1080 at the bottom edge. Hereinbelow, the image lines shall besometimes called lines. Also, each line is displayed in a displaydirection 120. That is, in the image display device 101 shown in FIG. 6(a), the image data is displayed in sequence from top to bottom at afixed cycle. In this case, data is displayed first at the topmost lineof the image display device 101, and the data is displayed 1080th at thebottommost line. One frame of the image data of each line is retaineduntil the next image data is displayed.

On the other hand, in the image display system 118 shown in FIG. 6 (b),four of the image display devices 101 shown in FIG. 6 (a) (shown as theimage display devices 101 a to 101 d in FIG. 6 (b)) are arranged side byside in the vertical direction. In this case, in the image displaysystem 118, the directions and orientations of the display direction 120a of the display unit 115 a, the display direction 120 b of the displayunit 115 b, the display direction 120 c of the display unit 115 c, andthe display direction 120 d of the display unit 115 d are all the same.

Next, referring to FIG. 7, a display example of a moving image in theimage display system 118 shown in FIG. 6 shall be described. FIG. 7 (a)is a front view that schematically shows an example of image data thatis displayed in the display unit 115 of the image display device 101.FIG. 7 (b) is a front view that schematically shows the display state ofa moving image in the image display system 118 in the case of causing avertical line 130 shown in FIG. 7 (a) to move in the moving direction ofthe arrows.

As shown in FIG. 7 (b), when a moving image is displayed by stacking aplurality of the image display devices 101 vertically, in the case ofthe image display device 101 with 1080 lines from top to bottom, thedata is displayed in 1080th place at the bottommost line of the upperside image display device 101 (for example, the image display device 101a), and one frame is retained. Meanwhile, the data is displayed in firstplace at the first line of the image display device on the lower side(for example, the image display device 101 b) that is adjacent with theupper side image display device 101 (in this example, the image displaydevice 101 a). That is to say, the vertical lines 130 a, 130 b, 130 cand 130 d that are displayed in the display units 115 a, 115 b, 115 c,and 115 d, respectively, are displayed with the 1080th line beingdelayed a maximum of one frame behind the first line in the direction ofprogress from 130 a to 130 d. For that reason, misalignment occurs inthe image at the interface between the image display device 101 (in thisexample, the image display device 101 a) and the image display device101 (in this example, the image display device 101 b) arranged side byside in the vertical direction. That is, misalignment is produced in theimage at the interface between the image display device 101 a at the topand the second image display device 101 b, between the second imagedisplay device 101 b and the third image display device 101 c, andbetween the third image display device 101 c and the fourth imagedisplay device 101 d.

The present invention has been achieved in view of the aforementionedcircumstances, and has as its an exemplary object to provide an imagedisplay device, an image display system, and an image display methodthat can suppress and decrease to a misalignment of a moving imageoccurring at the interfaces of at least two image display devicesarranged in a row.

Means for Solving the Problem

In order to solve the aforementioned problem, an image display device ofone exemplary aspect of the present invention includes: a display unitthat displays image data in a horizontal direction and a verticaldirection; a detection unit that detects presence of an input of apredetermined position information signal output from another imagedisplay device; a signal output control unit that instructs whether ornot to output a position information signal from the image displaydevice itself in accordance with a detection result by the detectionunit; a signal output unit that outputs the position information signalin a case of the signal output control unit instructing output of theposition information signal; a display direction switching control unitthat instructs switching of a vertical display direction to the displayunit in accordance with the detection result by the detection unit; animage data input unit that receives the image data; and an image datatransmission switching unit that switches a transmission order of eachimage line in accordance with the detection result by the detectionunit, and transmits to the display unit the image data received by theimage data input unit.

Also, an image display system of one exemplary aspect of the presentinvention includes a plurality of image display devices including: adisplay unit that displays image data in a horizontal direction and avertical direction; a detection unit that detects presence of an inputof a predetermined position information signal output from another imagedisplay device; a signal output control unit that instructs whether ornot to output a position information signal from the image displaydevice itself in accordance with a detection result by the detectionunit; a signal output unit that outputs the position information signalin a case of the signal output control unit instructing output of theposition information signal; a display direction switching control unitthat instructs switching of a vertical display direction to the displayunit in accordance with the detection result by the detection unit; animage data input unit that receives the image data; and an image datatransmission switching unit that switches a transmission order of eachimage line in accordance with the detection result by the detectionunit, and transmits to the display unit the image data received by theimage data input unit, and the image display system is constituted bythe plurality of image display devices being arranged side by side in aplurality in the vertical display direction.

Also, an image display method of one exemplary aspect of the presentinvention, by using: a display unit that displays image data in ahorizontal direction and a vertical direction; a detection unit thatdetects presence of an input of a predetermined position informationsignal output from another image display device; a signal output unitthat outputs a position information signal in a case of the signaloutput control unit instructing output of the position informationsignal; and an image data input unit that receives the image data; andincludes the steps of: instructing whether or not to output a positioninformation signal from the image display device itself in accordancewith a detection result by the detection unit; instructing switching ofa vertical display direction to the display unit in accordance with thedetection result by the detection unit; and switching a transmissionorder of image lines in accordance with a detection result by thedetection unit, and transmitting to the display unit image data receivedby the image data input unit.

Effect of the Invention

In the case of arranging the image display device of the presentinvention side by side in a plurality in for example the verticaldirection, it is possible to set them to mutually different orientationssuch that the vertical display direction of the odd-numbered imagedisplay devices counting from the bottom is made top-to-bottom, and thevertical display direction of the even-numbered image display devicescounting from the bottom is made bottom-to-top. In this case, it ispossible to match the display order of display lines at the interface ofthe odd-numbered image display devices and the even-numbered imagedisplay devices. Thereby, it is possible to suppress and decrease to amisalignment of a moving image produced at the interfaces of at leasttwo image display devices arranged in a row.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram that shows the constitution of one exemplaryembodiment of an image display device according to the presentinvention.

FIG. 2 is a front view that schematically shows an appearanceconstitution example of the image display device 1 shown in FIG. 1.

FIG. 3 is an explanatory view for describing the operation example ofthe image display device 1 shown in FIG. 1.

FIG. 4 is a front view for describing an operation example of the imagedisplay device 1 shown in FIG. 1.

FIG. 5 is a front view for describing an operation example of the imagedisplay device 1 shown in FIG. 1.

FIG. 6 is an explanatory view for describing the problem to be solved bythe present invention.

FIG. 7 is an explanatory view for describing the problem to be solved bythe present invention.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinbelow, one exemplary embodiment of an image display deviceaccording to the present invention shall be described with reference tothe drawings. FIG. 1 is a block diagram that shows the constitution ofthe one exemplary embodiment of the image display device according tothe present invention. The image display device 1 of the presentexemplary embodiment is constituted as a liquid crystal display device.The image display device 1 includes a detection unit 11, an infraredcontrol unit 12, an infrared transmission unit 13, a display methodswitching control unit 14, a liquid crystal display unit 15, an imagedata transmission switching unit 16, and an image data input unit 17.However, the image display device 1 of the present invention is notlimited to the case of being constituted as a liquid crystal displaydevice, and can be constituted as a display device that uses anotherdisplay medium.

The detection unit 11 detects the presence of an input of apredetermined position information signal transmitted from the infraredtransmission unit 13 of another image display device 1. Here, thepredetermined position information signal is for example an opticalradio signal such as an infrared modulation signal that representspredetermined data. The detection unit 11 can be constituted from aphotoelectric conversion element that converts an incident infraredsignal to an electrical signal, and a signal processing circuit forperforming a process that determines, based on that output signal,whether or not the predetermined position information signal has beeninput. The detection unit 11 outputs a signal indicating as a detectionresult the presence of the input of a predetermined position informationsignal transmitted from the infrared transmission unit 13 of anotherimage display device 1 to the infrared control unit 12, the displaydirection switching control unit 14, and the image data transmissionswitching unit 16.

Note that the predetermined position information signal is not limitedto an infrared signal, and may be a visible light signal. Also, it maybe a radio signal for short-range transmission. In addition, it is notlimited to a radio signal, and may be a wired signal. Note that aconstitution for the case of making it a wired signal shall be describedbelow.

The infrared control unit 12 is a signal processing circuit thatinstructs whether or not to output the position information signal fromthe same image display device 1 itself (that is, the infraredtransmission unit 13) in accordance with the detection result of thepredetermined position information signal by the detection unit 11. Theinfrared control unit 12 for example outputs a control signal thatinstructs the infrared transmission unit 13 to stop a positioninformation signal in the case of receiving a signal indicating thedetection result of detection of the predetermined position informationsignal from the detection unit 11. Also, the infrared control unit 12outputs a control signal that instructs the infrared transmission unit13 to output the position information signal in the case of receiving asignal indicating the detection result of non-detection of thepredetermined position information signal from the detection unit 11.

The infrared transmission unit 13 outputs the predetermined positioninformation signal in the case of the infrared control unit 12instructing output of the position information signal. Here, thepredetermined position information signal is the same or equivalentinfrared signal as the position information signal that the detectionsignal 11 detects, and for example, is an optical radio signal such asan infrared modulation signal that expresses predetermined data. Theposition control signal output from the infrared transmission unit 13becomes a signal for the detection unit 11 of another image displaydevice 1 to detect the presence of an input.

The display method switching control unit 14 is a signal processingcircuit that instructs switching of the direction of the verticaldisplay to the liquid crystal display unit 15 in accordance with thedetection result by the detection unit 11. In the case of a signalindicating the detection result of detection of the predeterminedposition information signal being received from the detection unit 11,the display method switching control unit 14 outputs to the liquidcrystal display unit 15 a signal instructing for example the displaydirection of an image to be made bottom-to-top. Also, in the case of asignal indicating the detection result of non-detection of thepredetermined position information signal being received from thedetection unit 11, the display method switching control unit 14 outputsto the liquid crystal display unit 15 a signal instructing for examplethe display direction of an image to be made top-to-bottom.

The liquid crystal display unit 15 is constituted from a liquid crystalpanel and drive control circuitry thereof, and based on image datareceived from the image data transmission switching unit 16, displays animage based on the image data while displaying in a horizontal andvertical manner. Also, the liquid crystal display unit 15, based on asignal instructing switching of the direction of the vertical displayinput from the display method switching control unit 14, performs imagedisplay by switching the image display direction to either of bottom totop or top to bottom.

The image data transmission switching unit 16 is a signal processingcircuit that, in accordance with the detection result of thepredetermined position information signal by the detection unit 11,switches the transmission order of each line of image data input to theimage data input unit 17 and transmits it to the liquid crystal displayunit 15. In the case of a signal indicating the detection result ofdetection of the predetermined position information signal beingreceived from the detection unit 11, the image data transmissionswitching unit 16 for example transmits the image data of each line tothe liquid crystal display unit 15 in the order of bottom to top in thevertical direction. Also, in the case of a signal indicating thedetection result of non-detection of the predetermined positioninformation signal being received from the detection unit 11, the imagedata transmission switching unit 16 for example transmits the image dataof each line to the liquid crystal display unit 15 in the order of topto bottom in the vertical direction.

The image data input unit 17 receives the image data to be displayed bythe liquid crystal display unit 15, and outputs it to the image datatransmission switching unit 16. The image data input unit 17 can receiveimage data from a predetermined storage device or a detachable storagemedium not shown that is provided in the image display device 1. Also,the image data input unit 17 can receive image data via a transmissioncable for image data that is connected to a predetermined input terminalor a predetermined communication network by using a predeterminedcommunication unit not illustrated that is provided within the imagedisplay device 1. Also, in the case of inputting image data via atransmission cable or a predetermined communication network, it ispossible to supply the image data from an external image data playbackdevice or from another image display device 1.

Next, the appearance configuration of the image display device 1 shownin FIG. 1 shall be described referring to FIG. 2. In FIG. 2, the samereference symbols used in FIG. 1 are used for the same or correspondingconstitutions. As shown in FIG. 2, the image display device 1 has adisplay surface of the liquid crystal display unit 15 at the front, anda portion (or all) of the detection unit 11 and the infraredtransmission unit 13 are provided outside the housing of the imagedisplay device 1. At least the light receiving surface and the lightemission surface of the detection unit 11 and the infrared transmissionunit 13 are provided outside the housing. In this case, the lightreceiving surface or the light emission surface may be provided so as tohave a projection on the outer portion of the housing. Alternatively,for example, by being provided in a cavity provided in the outer portionof the housing, or by being flush with the surface position, the lightreceiving surface and the light emission surface may need not have aprojection such that protrudes from the outer periphery of the housingto the outside. In this case, the detection unit 11 detects the presenceof the input of a position information signal (shown by the dotted arrowline) that is incident from one direction in the vertical direction ofthe liquid crystal display unit 15. Also, the infrared transmission unit13 outputs the position information signal (shown by the dotted arrowline) from the other direction in the vertical direction of the liquidcrystal display unit 15. Also, when the image display device 1 isinstalled side by side in the vertical display direction with anotherimage display device 1 as shown in FIG. 5, the detection unit 11 and theinfrared transmission unit 13 are arranged to face each other so thatthe infrared signal output from the detection unit 11 is received by theinfrared transmission unit 13. Note that, as shown in FIG. 2, in thepresent exemplary embodiment, the left-right direction of the liquidcrystal display unit 15 is the horizontal display direction, while thetop-bottom direction is the vertical display direction.

Referring to FIG. 3, the signal processing flow in the image displaydevice 1 shown in FIG. 1 shall be described. In FIG. 3, the samereference symbols used in FIG. 1 are used for the same or correspondingconstitutions. In FIG. 3, the processes performed by the detection unit11, the infrared control unit 12, the display method switching controlunit 14, or the image data transmission switching unit 16 shall beindicated by reference symbols prefixed with the letter “S”. Note thatthe image display device 1 can be used in a state of a plurality ofimage display devices 1 being arranged side by side in the verticaldisplay direction as shown in FIG. 5, and can be used in the state ofeach image display device 1 operating independently as shown in FIG. 4.

As shown in FIG. 3, the reception state of the infrared signal, which isthe position information signal, by the detection unit 11 is eitherinfrared reception (S11) or no infrared reception (S21). In the case ofthe infrared signal reception state of reception (S11), the detectionunit 17 judges the same image display device 1 itself to be arranged atan even-numbered level counting from the bottom, in the arrangement asshown in FIG. 5 (S12). In this case, the detection unit 11 outputs asignal indicating the detection result of detection of a positioninformation signal to the infrared control unit 12, the display methodswitching control unit 14, and the image data transmission switchingunit 16.

When a signal indicating the detection result of detection of a positioninformation signal is input from the detection unit 11, the infraredcontrol unit 12 stops the output of an infrared signal (S13). Also, whena signal indicating the detection result of detection of a positioninformation signal is input from the detection unit 11, the displaymethod switching control unit 14 outputs to the liquid crystal displayunit 15 a predetermined signal that switches the image display directionto bottom-to-top (S14). Also, when a signal indicating the detectionresult of detection of a position information signal is input from thedetection unit 11, the image data transmission switching unit 16switches the transmission order of image data to bottom-to-top, andsubsequently repeatedly performs output of image data to the liquidcrystal display unit 15 in this order (S15).

On the other hand, in the case of the infrared signal reception state ofno reception (S21), the detection unit 11 judges the image displaydevice 1 itself to be arranged at an odd-numbered level counting fromthe bottom, in the arrangement as shown in FIG. 5 (S22). In this case,the detection unit 11 outputs a signal indicating the detection resultof no detection of a position information signal to the infrared controlunit 12, the display method switching control unit 14, and the imagedata transmission switching unit 16.

When a signal indicating the detection result of no detection of aposition information signal is input from the detection unit 11, theimage data transmission switching unit 16 switches the transmissionorder of image data to top-to-bottom, and subsequently repeatedlyperforms output of image data to the liquid crystal display unit 15 inthis order (S23). Also, when a signal indicating the detection result ofno detection of a position information signal is input from thedetection unit 11, the display method switching control unit 14 outputsto the liquid crystal display unit 15 a predetermined signal thatswitches the image display direction to top-to-bottom (S24). Also, whena signal indicating the detection result of no detection of a positioninformation signal is input from the detection unit 11, the infraredcontrol unit 12 starts the output of an infrared signal (or continues itin the case of already being started) (S25).

Next, operation examples of the case of using a plurality of the imagedisplay device 1 shown in FIG. 1 shall be described, referring to FIG. 4and FIG. 5. FIG. 4 shows the case of each image display device 1 beingarranged at an interval exceeding the distance which the positioninformation signal can reach. FIG. 5 shows the case of a plurality ofthe image display devices 1 being arranged side by side in the directionof vertical display of the liquid crystal display unit 15. In theinstallation example of FIG. 5, each image display device 1 is installedat in interval within the distance which the position information signalcan reach. Note that in FIG. 4 and FIG. 5, by adding the Roman letters“a”, “b”, “c” and “d” to the end of the reference symbols used in FIG.2, the same constitutions are shown. Here, the image display device 1 awith the letter “a” added to the end is the image display device 1 thatis arranged at the top among the four. Similarly, the image displaydevices 1 b, 1 c, and 1 d are the image display devices 1 arrangedsecond, third, and fourth from the top, respectively. Also, among theinfrared transmission units 13 a, 13 b, 13 c and 13 d, those outputtingan infrared signal are shown by the diagonal hatching.

As shown in FIG. 4, in the case of each of the image display devices 1a, 1 b, 1 c, and 1 d being arranged at an interval exceeding thedistance which the position information signal can reach, each of thedetection units 11 a, 11 b, 11 c and 11 d do not detect a positioninformation signal. That is, the detection units 11 a, 11 b, 11 c and 11d perform the determination of there being no infrared reception (S21)and the process of odd-numbered level installation judgment (S22) inFIG. 3. Accordingly, each infrared control unit 12 instructs infraredsignal output (S25), and the infrared transmission units 13 a, 13 b, 13c and 13 d output an infrared signal (enter the hatched state). Also, asshown by the arrows 20 a, 20 b, 20 c and 20 d, the image data iscontrolled to be top-to-bottom by each image data transmission switchingunit 12 (S23), and the image display direction is controlled to betop-to-bottom by each display direction switching control unit 14 (S24).In this case, when displaying a moving image that moves the verticalline 130 as described referring to FIG. 7 (a), the same display stateresults in each of the image display devices 1 a, 1 b, 1 c and 1 d inthe same manner as shown in FIG. 7 (b). However, unlike the imagedisplay devices 101 a, 101 b, 101 c and 101 d of FIG. 7 (b), the imagedisplay devices 1 a, 1 b, 1 c and 1 d are installed separated by atleast a certain distance.

On the other hand, in the case of each of the image display devices 1 a,1 b, 1 c and 1 d being installed within a distance which the positioninformation signal can reach as shown in FIG. 5, the infraredtransmission unit 13 d at the bottom and the infrared transmission unit13 b at second level higher than that output infrared signals (as shownby the hatched state), while the infrared transmission unit 13 a at thetop and the infrared transmission unit 13 c on the third level do notoutput infrared signals (as shown by the non-hatched state).

That is, the infrared transmission unit 13 d at the bottom has noinfrared reception (S21), and therefore the image display device 1 d isjudged by the detection unit 11 d to be installed at an odd-numberedlevel counting from the bottom (S22). Also, the infrared transmissionunit 13 d outputs an infrared signal (S25). In addition, as shown by thearrow 21 d, the image data is controlled to be top-to-bottom by theimage data transmission switching unit 16 (S23), and the image displaydirection is controlled to be top-to-bottom by the display directionswitching control unit 14 (S24).

Next, the detection unit 11 c of the image display device 1 c that issecond from the bottom detects the infrared signal that is output fromthe infrared transmission unit 13 d (S11). In this case, the imagedisplay device 1 c is judged by the detection unit 11 c to be installedat an even-numbered level counting from the bottom (S12). Also, theinfrared transmission unit 13 c stops the infrared signal (S13). Inaddition, as shown by the arrow 21 c, the image display direction iscontrolled to be bottom-to-top by the display direction switchingcontrol unit 14 (S14), and the image data is controlled to bebottom-to-top by the image data transmission switching unit 16 (S15).

Next, the infrared transmission unit 13 b that is third from the bottomhas no infrared reception (S21), and therefore the image display device1 b is judged by the detection unit 11 b to be installed at anodd-numbered level counting from the bottom (S22). Also, the infraredtransmission unit 13 b outputs an infrared signal (S25). In addition, asshown by the arrow 21 b, the image data is controlled to betop-to-bottom by the image data transmission switching unit 16 (S23),and the image display direction is controlled to be top-to-bottom by thedisplay direction switching control unit 14 (S24).

Then, the detection unit 11 a of the image display device 1 a that isfourth from the bottom detects the infrared signal that is output fromthe infrared transmission unit 13 b (S11). In this case, the imagedisplay device 1 a is judged by the detection unit 11 a to be installedat an even-numbered level counting from the bottom (S12). Also, theinfrared transmission unit 13 a stops the infrared signal (S13). Inaddition, as shown by the arrow 21 a, the image display direction iscontrolled to be bottom-to-top by the display direction switchingcontrol unit 14 (S14), and the image data is controlled to bebottom-to-top by the image data transmission switching unit 16 (S15).

In the aforementioned case, the interface between the image displaydevice 1 a and the image display device 1 b and the interface betweenthe image display device 1 c and the image display device 1 d become thedisplay line for the first line in the image display device 1 a, theimage display device 1 b, the image display device 1 c, and the imagedisplay device 1 d. On the other hand, the interface between the imagedisplay device 1 b and the image display device 1 c becomes the displayline for the 1080th line. Thereby, the display timing is synchronizedsince image display is performed at the same time at the display linesat the upper side of the image display devices 1 d and 1 b, which are onodd-numbered levels from the bottom, and at the display lines at thelower side of the image display devices 1 c and 1 a, which are arrangedon the upper side to be adjacent thereto and are on even-numbered levelsfrom the bottom. Similarly, since the display lines at the upper side ofthe even-numbered levels from the bottom and the display lines of theodd-numbered levels from the bottom that are arranged to be adjacentthereto are displayed at the end of one frame, synchronization of thedisplay timing is similarly obtained. Thereby, even when displaying amoving image in multi-tiling of two levels or more, it becomes possibleto perform display with no misalignment of the image. For that reason,when moving the vertical line 130 shown in FIG. 7 (a) in the movingdirection of the arrows, the vertical lines 31 a, 31 b, 31 c, and 31 ddisplayed in the respective display units 15 a, 15 b, 15 c, and 15 d ofthe image display devices 1 a, 1 b, 1 c, and 1 d become images that movethrough nearly the same position in the horizontal direction at eachinterface. That is, it is possible to eliminate misalignment at eachinterface of the image display devices 1 a, 1 b, 1 c, and 1 d.

In the above manner, the display direction of image data istop-to-bottom at the first level from the bottom, bottom-to-top at thesecond level from the bottom, top-to-bottom at the third level from thebottom, and bottom-to-top at the fourth level from the bottom. Thereby,since image data is displayed at the same timing at the interface ofeach image display device 1, there is no misalignment even whendisplaying moving images. By doing so, by providing a function to changethe display direction of image data, and an infrared transmission unitand detection unit for position detection of the even-numbered levelsand odd-numbered levels in the image display device 1 of the presentexemplary embodiment, even when displaying a moving image in amulti-tiling application that is installed across a plurality of levels,it is possible to display images with no moving image misalignmentoccurring at the interfaces of the image display devices 1.

In the aforementioned exemplary embodiment, detection of the position isperformed by providing the infrared transmission unit 13 and thedetection unit 11 for detection of the position of the image displaydevice 1, but it is also possible to determine the position informationin the same manner by having a position information output terminal andan input terminal and connecting them with a cable, instead of theinfrared transmission unit 13 and the detection unit 11 for radiosignals. In this case, the position information output terminal and theinput terminal are respectively associated with either one or the otherof the vertical display directions of the liquid crystal display unit15. That is to say, the presence of a predetermined wired signal that isinput from a predetermined input terminal associated with one verticaldisplay direction of the liquid crystal display unit 15 is detected asthe presence of an input of the aforementioned position informationsignal. Also, the signal output unit of the wired signal correspondingto the infrared transmission unit 13 serves to output the aforementionedposition information signal by outputting a predetermined wired signalfrom a predetermined signal information output terminal that isassociated with the other vertical display direction of the liquidcrystal display unit 15.

Also, the effect is the same even in the case of continuously installingside by side horizontally the image display device 1 stacked over aplurality of levels in the aforementioned exemplary embodiment. That is,there is no change in the effect of reducing misalignment at eachinterface between image display devices 1 arranged vertically.

Also, a program for realizing all or some of the functions of each unitin FIG. 1 may be recorded on a computer-readable recording medium, andby reading the program that is recorded on this recording medium into acomputer system and running it, each process may be performed. Note thata “computer system” here includes an operating system and hardware suchas peripheral devices.

Also, the “computer system” in the case of using a WWW system alsoinclude a homepage providing environment (or display environment).

Furthermore, the “computer-readable recording medium” refers to aportable medium such as a flexible disk, a magneto-optical disk, ROM,CD-ROM and the like, or a storage device such as a hard disk that ishoused in a computer system. Moreover the “computer-readable recordingmedium” also includes a recording medium that retains a program for agiven period of time, such as a volatile memory in a computer systemthat functions as a server or client. The abovementioned program may beone for realizing some of the functions described above, and moreovermay be one capable of realizing the abovementioned functions incombination with a program that has already been stored in the computersystem. Further, the program described above may be stored in apredetermined server, and may be distributed (downloaded and the like)via communication lines in accordance with a request from anotherdevice.

While the exemplary embodiment of this invention has been describedabove in detail with reference to the drawings, a concrete configurationis not limited to this exemplary embodiment, and designs or the like ina range not departing from the scope of the present invention are alsoincluded.

While the exemplary embodiment of the present invention has beendescribed above in detail with reference to the drawings, a concreteconfiguration is not limited to this exemplary embodiment, and designsor the like in a range not departing from the scope of the presentinvention are also included.

[Supplementary Note 1]

An image display device including: a display unit that displays imagedata in a horizontal direction and a vertical direction; a detectionunit that detects presence of an input of a predetermined positioninformation signal output from another image display device; a signaloutput control unit that instructs whether or not to output a positioninformation signal from the image display device itself in accordancewith a detection result by the detection unit; a signal output unit thatoutputs the position information signal in a case of the signal outputcontrol unit instructing output of the position information signal; adisplay direction switching control unit that instructs switching of avertical display direction to the display unit in accordance with thedetection result by the detection unit; an image data input unit thatreceives the image data; and an image data transmission switching unitthat switches a transmission order of each image line in accordance withthe detection result by the detection unit, and transmits to the displayunit the image data received by the image data input unit.

[Supplementary Note 2]

The image display device according to supplementary note 2, wherein theposition information signal is an optical radio signal, the detectionunit detects presence of a predetermined optical radio signal that isincident from one direction of the vertical direction of the displayunit as the presence of the input of the position information signal,and the signal output unit emits a predetermined optical radio signalfrom other direction in the vertical direction of the display unit tothereby output the position information signal.

[Supplementary Note 3]

The image display device according to supplementary note 1, wherein theposition information signal is a wired signal, the detection unitdetects presence of a predetermined wired signal as the presence of theinput of the position information signal, the predetermined wired signalbeing input from a predetermined input terminal that is associated withone direction of the vertical direction of the display unit, and thesignal output unit outputs a predetermined wired signal from apredetermined output terminal that is associated with other direction inthe vertical direction of the display unit, to thereby output theposition information signal.

[Supplementary Note 4]

An image display system including a plurality of image display devicesincluding: a display unit that displays image data in a horizontaldirection and a vertical direction; a detection unit that detectspresence of an input of a predetermined position information signaloutput from another image display device; a signal output control unitthat instructs whether or not to output a position information signalfrom the image display device itself in accordance with a detectionresult by the detection unit; a signal output unit that outputs theposition information signal in a case of the signal output control unitinstructing output of the position information signal; a displaydirection switching control unit that instructs switching of a verticaldisplay direction to the display unit in accordance with the detectionresult by the detection unit; an image data input unit that receives theimage data; and an image data transmission switching unit that switchesa transmission order of each image line in accordance with the detectionresult by the detection unit, and transmits to the display unit theimage data received by the image data input unit, wherein the imagedisplay system is constituted by the plurality of image display devicesbeing arranged side by side in a plurality in the vertical displaydirection.

[Supplementary Note 5]

An image display method by using: a display unit that displays imagedata in a horizontal direction and a vertical direction; a detectionunit that detects presence of an input of a predetermined positioninformation signal output from another image display device; a signaloutput unit that outputs a position information signal in a case of thesignal output control unit instructing output of the positioninformation signal; and an image data input unit that receives the imagedata; and including the steps of: instructing whether or not to output aposition information signal from the image display device itself inaccordance with a detection result by the detection unit; instructingswitching of a vertical display direction to the display unit inaccordance with the detection result by the detection unit; andswitching a transmission order of image lines in accordance with adetection result by the detection unit, and transmitting to the displayunit image data received by the image data input unit.

REFERENCE SYMBOLS

-   -   1, 1 a, 1 b, 1 d Image display device (image display device)    -   11, 11 a, 11 b, 11 c, 11 d Detection unit (detection unit)    -   12 Infrared control unit (signal output control unit)    -   13, 13 a, 13 b, 13 c, 13 d Infrared transmission unit (signal        output unit)    -   14 Display direction switching control unit (display direction        switching control unit)    -   15, 15 a, 15 b, 15 c, 15 d Liquid crystal display unit (display        unit)    -   16 Image data transmission switching unit (image data        transmission switching unit)    -   17 Image data input unit (image data input unit)

1. An image display device comprising: a display unit that includes aplurality of display lines; a detection circuit that judges whether theimage display device is installed at an odd-numbered level or at aneven-numbered level by detecting a predetermined position informationsignal output from another image display device; an image data inputunit that receives image data including data for each display line; andan image data transmission switching circuit that switches atransmission order of the data for each display line in accordance withwhether the image display device is installed at the odd-numbered levelor at the even-numbered level, and transmits to the display unit theimage data including the data for each display line whose transmissionorder is switched, wherein the display unit displays the transmittedimage data.
 2. The image display device according to claim 1, whereinthe detection circuit judges that the image display device is installedat an odd-numbered level counted from a bottom when the detectioncircuit has detected the predetermined position information signal, andthe detection circuit judges that the image display device is installedat an even-numbered level counted from the bottom when the detectioncircuit has not detected the predetermined position information signal.3. The image display device according to claim 1, further comprising: asignal output control circuit that instructs whether to output aposition information signal from the image display device in accordancewith a detection result by the detection circuit.
 4. The image displaydevice according to claim 3, further comprising: a signal output unitthat outputs the position information signal in a case of the signaloutput control unit instructing output of the position informationsignal.
 5. The image display device according to claim 4, furthercomprising: a display direction switching control circuit that instructsswitching of a vertical display direction to the display unit inaccordance with the detection result by the detection circuit.
 6. Theimage display device according to claim 5, wherein the detection circuitoutputs a signal indicating the detection result to the signal outputcontrol circuit, the display direction switching control circuit, andthe image data transmission switching circuit.
 7. The image displaydevice according to claim 5, wherein if the detection result indicatesdetection of the predetermined position information signal, then thedisplay direction switching control circuit outputs to the display unita signal instructing the display direction to be one of top-to-bottomand bottom-to-top in the vertical direction, and wherein if thedetection result indicates non-detection of the predetermined positioninformation signal, then the display direction switching control circuitoutputs to the display unit a signal instructing the display directionto be the other of top-to-bottom and bottom-to-top in the verticaldirection.
 8. The image display device according to claim 1, wherein theposition information signal detected by the detection circuit comprisesan optical signal representing predetermined data, and wherein thedetection circuit comprises: a photoelectric conversion element thatconverts the optical signal to an electrical signal; and a signalprocessing circuit for determining based on the electrical signal,whether the predetermined position information signal has been input tothe image di splay device.
 9. The image display device according toclaim 1, wherein if the detection result indicates detection of thepredetermined position information signal, then the image datatransmission switching circuit transmits the image data of each line tothe display unit from one of top-to-bottom and bottom to top in thevertical direction, and wherein if the detection result indicatesnon-detection of the predetermined position information signal, then theimage data transmission switching circuit transmits the image data ofeach line to the display unit from the other of top-to-bottom andbottom-to-top in the vertical direction.
 10. The image display deviceaccording to claim 1, wherein the position information signal is anoptical radio signal, and the detection circuit detects a predeterminedoptical radio signal that is incident from a first direction along avertical display direction as the position information signal.
 11. Theimage display device according to claim 1, wherein the positioninformation signal is a wired signal, and the detection circuit detectsa predetermined wired signal as the position information signal, thepredetermined wired signal being input from a predetermined inputterminal that is associated with a first direction along a verticaldisplay direction.
 12. A method for an image display device, the imagedisplay device including a display unit, the display unit including aplurality of display lines, the method comprising: judging whether theimage display device is installed at an odd-numbered level or at aneven-numbered level by detecting a predetermined position informationsignal output from another image display device; receiving image dataincluding data for each display line; switching a transmission order ofthe data for each display line in accordance with whether the imagedisplay device is installed at the odd-numbered level or at theeven-numbered level; transmitting to the display unit the image dataincluding the data for each display line whose transmission order isswitched; and displaying the transmitted image data by the display unit.13. An image display device comprising: a display unit that includes aplurality of display lines; an image data input unit that receives imagedata including data for each display line; and an image datatransmission switching circuit that transmits to the display unit theimage data including the data for each display line whose transmissionorder is from one of top-to-bottom and bottom-to-top if the imagedisplay device is installed at an odd-numbered level, and transmits tothe display unit the image data including the data for each display linewhose transmission order is from the other of top-to-bottom andbottom-to-top if the image display device is installed at aneven-numbered level, wherein the display unit displays the transmittedimage data.